It is possible to quickly align an object with an axis of a custom transformation?
Tell me if this is what you want:


Create you first object and rotate it.
Create your second object, put its origine on its base (with Cursor to Selected then Origin to Cursor).
Activate the Snap tool of your horizontal menu bar, choose Face mode, enable all options.
Grab your second object, it will snap on the surface of the first one.
You can assign an Array modifier to your object so that it duplicates along.